Bacterial growth in absorbent dressings for wounds, urinary incontinence diapers, and menstruation pads can lead to serious medical complications as well as social difficulties. For example, bacterial growth in urinary incontinence diapers or menstruation pads usually produces among, unpleasant odors that are socially unacceptable and can cause persons to alter their lifestyle. Conventional absorbent pads for urinary incontinence and menstruation are not inherently bactericidal. Consequently, the only way to avoid growth of bacteria in the absorbent dressings is to change them at frequent intervals, even if the absorbent capacity of the pad has not been reached. In the area of wound dressings, bacterial contamination of acute wounds and infection of chronic skin wounds are major clinical problems that can result in significant morbidity and, in severe cases, mortality. Conventionally, wound dressings have been designed to absorb wound fluids and yet provide a moist environment for promoting wound healing. However, such moist environments create a nutrient rich reservoir for bacterial growth in the dressing. Bacteria growing in the dressing can be shed back into the wound, increasing the risk of wound infection, or response to toxins, and producing strong, foul odors.
In an effort to address these problems, antibiotics or chemical disinfectants are frequently applied topically to wounds prior to covering the wound with a dressing. Alternatively, topical agents are sometimes applied directly to the surface of the dressing. To control foul odors, some known dressings incorporate charcoal powder to absorb molecules generating the foul odor. For some applications, topical application of antibacterial agents is not desirable. For instance, bactericidal agents applied topically to wound dressings have a tendency to seep into the wound being treated. Furthermore, many antimicrobial drugs, such as iodine, are cytotoxic and will retard wound healing if used repetitively or at high concentrations.
A composition comprising a superabsorbent polymer having a monolayer (or near monolayer) of silane antimicrobial agent in a covalent bonding relationship with the base polymer is disclosed in U.S. Pat. No. 5,045,322. The composition may be in the form of flakes, strips, powders, filaments, fibers or films, and may be applied to a substrate in the form of a coating. The aforementioned composition is less apt to enter a wound vis-a-vis conventional topical treatment systems. In that respect, the disclosed composition provides an improvement over conventional topical treatment systems. However, silanes contain siloxane bonds which can be cleaved by acids and bases produced by infection or bacterial growth. In turn, these reactions may weaken or destroy bends between the silane antimicrobial agent and the underlying polymer. Consequently, antimicrobial agent may seep into a wound and retard wound healing.
The need exists for an improved antimicrobial dressing composition having an antimicrobial agent which can be maintained securely attached to a superabsorbent polymer upon exposure to acids and bases produced by infection and bacterial growth. In addition to reducing the propensity for detachment of the antimicrobial agent, it would be desirable to provide a surface area enhanced dressing structure for increasing the effectiveness of the antimicrobial agent.